Aircraft

ABSTRACT

The inventive aircraft with off-aerodrome landing consists of a body ( 1 ), a lifting wing ( 2 ) and the onboard part of a rope arresting and landing device comprising an arresting hook ( 5 ) which is provided with a grip ( 6 ). In the preferred embodiment, said aircraft is provided with a propeller ( 3 ) arranged in an annular empennage ( 4 ). Said arresting hook is arranged in such a way that it is rotatable around the transversal axis ( 8 ) of the aircraft situated in a longitudinal spacing of the aerodynamic mean chord of the wing. The aircraft leads for landing with the upwardly deployed arresting hook in such a way that the trajectory ( 12 ) of a top pickup point ( 6 ) is higher than the trajectory ( 13 ) of the highest top point of the aircraft and higher than a cable or rope ( 14 ) tensed on a landing area. The trajectory ( 13 ′) of the highest point of the aircraft located ahead of the arresting hook passes at a lower level than the cable ( 14 ). In said conditions, the grip of the arresting hook holds the cable which has a required effort for drawing it from a stationary arresting device. By overcoming said effort the aircraft spends a flight kinetic energy and stops being suspended on the cable.

FIELD OF THE INVENTION

The present invention relates to aviation equipment, and more particularly to the aircraft design (airplanes, gliders and flying airplane models) with off-aerodrome landing,

BACKGROUND OF THE INVENTION

Except for the vertical takeoff and landing aircrafts characterized by many generally known disadvantages, including their unavailability for commercial applications, all other known off-aerodrome landing aircrafts are divided into two groups.

One off-aerodrome landing aircrafts group comprises the devices equipped with parachutes. The second group off-aerodrome landing aircrafts is represented by the manned airplanes equipped with landing cable devices (here the cable is understood as any flexible connection performed by rope, cable, chain, etc.).

In the landing system (SU # 1837038, Int. Cl.⁷ B 64 F 1/02, 30.08.90), a manned airplane is used where a grip lock is provided into the front fuselage, and on an airfield at the height exceeding approximately twice the airplane length, a cable is strained between two oppositely located rods. Each rod is established with an option of moving in the air—hydraulic shock-absorber cylinder placed on two-degree-of-freedom suspension on the jib crane, controlled by hydraulic cylinders. In the landing mode the cable position and tension are automatically stabilized.

For landing the airplane is set to overcritical attack angles providing almost vertical airplane position with the help of engines traction. Then the landing speed and flight height are reduced. At the airplane approach to the landing place the fuselage fairing head part is opened, the hydraulic cylinders putting forward the traverse with the grip rigidly established in front of the traverse crosspiece. Thus, the grip both in removed and in deployed positions is connected to the airplane fuselage by hydraulic cylinders that is sufficiently rigid, and such system can be attributed to the flying catches (hooks) intended for near-zero approach speed to the catching position. The halves of the opened fairing form a trap in the form of an opening equipped with deep cam lock grip. The trap is directed almost horizontal aside the cable. At the airplane achievement of the flight speed close to zero in respect to the cable, the trap slowly approaches against the cable to the stop a cable in a grip. The grip approaching the cable causes a turn of the lock cams and a lock of the cable grip. Then by inertia and weight of the airplane the cable takes loop-like form due to exit of rods from the shock-absorber cylinders, and the system cable—airplane—shock-absorbers becomes a physical pendulum which rocking is compensated by the shock-absorbers. Then the engines are cut off; the landing of the airplane to the cable is completed.

The airplane appears suspended at the nose part to the cable with the tail unit downwards. Then with the help of the jib cranes hydraulic cylinders the airplane in the suspended position is transported and established on the deck vertically (like a rocket) on the tail assembly.

The airplane with such system of landing demands:

-   -   a) Engines with total traction force exceeding the aircraft         weight, for the landing maneuver fulfillment—transition from the         normal flight to the stalling flight, and maintenance of almost         vertical flight—hanging;     -   b) Complex control system of the aircraft;     -   c) Additional fuel for performance of complex landing maneuver,     -   d) Pilot of the highest qualification;     -   e) Better durability of the aft fuselage.

The drawbacks include inconvenience of the pilots placing owing to the aircraft vertical standing position.

There is no information on practical application of such landing system.

Most types of aircrafts, including the aircraft models, gliders and unmanned airplanes, do not meet the said requirements, and therefore are unsuitable for such cable landing technique.

However, the airplane cable landing device applied in this system is suitable to use both without any changes, and with significant simplifications for the landing of aircraft models, gliders and unmanned airplanes according to the proposed invention.

In another known cable system (RU #2067951, Int. Cl.C⁷ B 64 C 25/68, 20.10.96) the cable is applied to shorten the landing run of the airplane landing on the aircraft carrier deck. (The cable landing technique included in this system has been known since 1911 and is widely applied in the aircraft carriers.)

The four arresting cables of the brake device stationary part are stained at height 0.10-0.12 meters across and at the beginning off the runway. The said brake device also including the brake drums with the rope ends reeled up on them.

Each airplane comprises the brake device onboard part including the arresting hook with grip, the shock-absorber and the actuation gear of the hook. The arresting hook, as a rule, is realized by the round shaft named a bar or a shank (force element), on the deployed end thereof a grip (catching element) is established, and the opposite bar end is fixed in the aft fuselage with an opportunity of swing around the aircraft transversal axis. The exception includes the arresting hook design in which the bar fastening end is realized by traverse with two shoulders fastened coaxially outside the boards of the aft fuselage.

Before the airplane goes on landing, the actuation gear turns the hook from removed into the deployed position in which the arresting hook deployed end with a grip is located below the fuselage, and by the moment of landing the extreme trajectory of the hook deployed end passes below trajectories of any point of the airplane.

At the airplane landing on the deck the arresting hook is engaged by the grip at one of four cables. The shock-absorber damps the arresting hook deviations, and the cable gripped by the arresting hook has the pre-set effort for unwinding from the brake drums. By overcoming this efforts the airplane spends the kinetic energy, extends the cable loop from drums, and runs along the deck no more than 90 meters and stops.

The drawbacks of the aircraft applied to this system are the following:

-   -   a) Necessity for the high qualification pilot, since the landing         is carried out by an inclined trajectory (angle of descent −4°)         on the platform in the size of 6×36 meters with catching of the         grip by the cable not earlier than the main gear touches down         the deck. At earlier catching, the aircraft receives from the         cable braking effort initially small pitching up moment, which         after ¼ second from the catching turns into the increasing         pitching down moment. However, the most important is the         airplane receiving an additional touch-down velocity up to 0.7         m/s from the braking force vertical component, and at 0.5 second         from the catch moment—up to 2 m/s. Therefore the subsequent         airplane landing occurs at the increased vertical speed,         especially lowering speed of the nose gear up to its breakage         (this phenomenon is called a “whip” in the professional slang);     -   b) The increased airplane weight not less than on 15% (to         increase the durability of the center and aft fuselage         compartments to which the main gear and the arresting hook are         attached, and to increase the durability and heights of the main         and nose gears to sustain the airplane landing with vertical         speed up to 7,5 m/s);     -   c) Unreliable catching mode, especially in storm, causing a high         probability of repeated landing attempt (to increase the         gripping probability several arresting cables equipped with the         brake drams are engaged in parallel);     -   d) High price of the airplane (basically, due to the         disadvantages mentioned above);     -   e) High price of the stationary landing equipment (the ship with         a landing deck in length not less than 120 meters);     -   f) High cost of the pilot training (up to ten million US         dollars—according to the American data);     -   g) Limited application of such airplanes (only for the military         purposes and only on aircraft carriers).     -   The second group of off-aerodrome landing aircrafts comprises         the devices equipped with parachutes. So the device (U.S. Pat.         No. 4,311,290, U.S.Cl. 244/110R, Int.Cl.⁷ B64 F 1/02, 19.01.82),         chosen as a prototype which provides the availability of a         paraplane on the aircraft (feature “brake device onboard part”)         is known.

For landing this aircraft to a vessel a mast with rotary arrow equipped with arresting hooks and jib turn disk brake device (feature “brake device stationary part”) is provided

The paraplane comprises a canopy (feature “gripping element”) and from the guy set included in two slings (feature “force element”). The canopy is executed from fabric or film material to provide the canopy wing shape in the deployed position. The slings are located symmetrically in respect the aircraft main base axis, the places of their fastening are either on the fuselage, or on the wing (feature “force element”-“gripped element connection to the aircraft”). For preservation of the controlled flight of the paraplane—aircraft system, the resulting force from the paraplane canopy is applied to the point usually higher than the aircraft mass center, and near to the mass center in the longitudinal direction. The latter of the aircraft realized by the conventional aerodynamic circuit is kept within the limits of the wing mean aerodynamic chord (for example, for plane Jak-40 the limiting centering makes 13-32% of the mean aerodynamic chord, see. L. E. Bogoslovsky, Practical Aerodynamics of the Airplane Jak-40, M., Transport, 1975, pp. 33-39). Thus, depending on the wind speed, size and direction of the engines draft (if any) and so forth, there can be a small deviation of the resulting force application point from the aircraft center of mass (features—“force element”-“fixed on the aircraft with an opportunity of turn around the aircraft traversal axis located in the longitudinal interval of the mean aerodynamic chord”).

Before landing a paraplane is deployed from the aircraft, the paraplane canopy under action of accumulating air stream is opened by a jerk and takes the wing form which settles above the aircraft (feature—“gripped element”-“established with an opportunity of extension above the aircraft going on landing”). The aircraft-paraplane system is directed to the landing place in such a way that the aircraft goes under the mast jib, and the paraplane canopy goes above the said jib. In result the canopy is fixed by the jib arresting hooks, the jib by the hooked aircraft inertia turns and inclines, spending the aircraft kinetic energy for break of the stud supporting the jib in initial horizontal position, and for overcoming the braking force of the disk brake device at the jib turn around the mast at one quarter of revolution. Thus the aircraft by vertical braking goes upwards, and then turns at one quarter of revolution together with the jib, falling by gravity and being shaken in two mutually perpendicular vertical planes.

After the termination of rocking (in one plane this is promoted by the working engine) the aircraft landing “on a hook” is completed. The final suspended position of the aircraft is close to horizontal (some deviation of the pitch angle is inevitable, owing to changes of the aircraft centering and necessity of the controllability requirement observance of the aircraft-paraplane system at approaching to the landing mast). Then the brake is put off and, with the help of the jib the aircraft is lowered on the landing surface (water or ship deck).

The disadvantages of such aircraft are the following:

-   -   a. The necessity to have onboard the paraplane and the paraplane         operation serving devices (for example, two obligatory symmetric         points of paraplane fastening to the aircraft appreciably         complicate the paraplane stacking compartment design) is up to         20% of the maximal carrying capacity and up to 100% of the         aircraft service cost;     -   b. Significant probability of abnormal situations connected to         the paraplane (failed opening, folding of the opened paraplane         by air pulse, etc.);     -   c. Inconveniences of post-landing paraplane servicing

There is no information on application of such devices available, obviously, owing to the listed above disadvantages.—

Another such airplane with the cable landing (U.S. Pat. No. 2,488,050. U.S. Cl. 244/110. Nov. 15, 1949), chosen as a prototype, whose landing device is equipped with a supporting cable. Along this cable a trolley can move with a catching sling across and below the supporting cable. The aircraft has an arresting hook with a grip placed with the capability of extending up the landing aircraft which for landing flies under the catching sling.

The object of this invention is a device, which transmits the braking force to the aircraft alone the line passing through the aircraft center of mass. For this purpose, the transversal axis of the arresting hook is located immobile with respect to the moved support. Befor landing the support is moved with a drive (controlled by the pilot) so that the transversal rotation axis would pass through the aircraft center of mass calculated for the time of landing. As a result of catching the grip with the catching sling, the braking force is applied from the catching sling through the arresting hook to the aircraft by the center of mass thereof, and therefore, there is no pitching moment (M) in the course of the flight braking. Therefore all over the period of the flight braking the aircraft retains practically level position.

The advantages of this aircraft in respect to the second analogue are the following:

-   -   a. Absence of “whip” effect;     -   b. Reduction in requirements to the pilot qualification;     -   c. Reduction in cost (ship, pilot training of and the aircraft         itself).

The disadvantages of the said aircraft are more complex and cost design (required a support device of the arresting hook), more difficult piloting due to support motion operation with preliminary calculation of the center of mass, and increase by 5 and more percent of empty aircraft mass on the account of additional device. All these disadvantages decrease reliability (there is probability of aircraft crash because of incorrect putting of the support) and application field of the cable landing, especially for the unmanned light aircraft

DESCRIPTION OF THE INVENTION

The purpose of the present invention is elimination of the specified disadvantages of the prototype (at preservation of the above listed advantages), namely, increase of carrying capacity, reduction of—service—cost, increase of landing reliability, and also resolution of common fault of all above listed analogues-expansion of application field (arsenal) of the aircrafts with off-aerodrome landing, including civil passenger airplanes, gliders, flying airplane models and unmanned airplanes.

The problem in view is resolved by the aircraft comprising a fuselage, a lifting wing and onboard part of the landing and braking device, including the

-   -   gripped element placed with possibility of letting out above the         landing aircraft and intended to engage by the catching element         of the stationary part of the brake device situated at the         landing site, and also comprising the force element connecting         the gripping element with the aircraft and fixed on the aircraft         with opportunity of turning around the transversal axis of         aircraft located in the longitudinal interval of the mean         aerodynamic chord of the wing, according to the invention, force         and gripped elements represent an arresting hook with a grip.

In the aircraft the transversal axis of turning of the arresting hook can be located in the center of mass of the landing aircraft.

In the aircraft

-   an arresting hook with a grip, this hook placed with possibilities     of letting out of the grip above the landing aircraft in order to     endue the grip with the catching cable of the stationary part of the     landing and braking device and -   of turning around the transversal axis under influence of braking     force—as result of engagement, said transversal axis located within     the longitudinal interval of the mean aerodynamic chord of the wing,     according to the invention the transversal axis of turning of the     arresting hook can be located above and behind the center of mass of     the aircraft.

In the aircraft the transversal axis of turning of the arresting hook can be located immobile with respect to aircraft.

In the aircraft the arresting hook fixed outside the fuselage and can be made as two bars located symmetrically in respect to the aircraft center line, and the crosspiece connecting the extended ends of the bars and comprising a grip with a lock

In the aircraft the arresting hook can be mounted with ability of terning into the removed position in which the bats adjoin to the fuselage external surfilce.

The distinguishing features of the claimed invention (arresting hook with a grip) are known from the prior art. The technical result of these features is known as an opportunity of the aircraft deck landing due to braking of a landing run by the cable brake device. The new basic technical result is an opportunity of landing to a cable of a many kinds of aircrafts (expansion of the off-aerodrome landing arsenal) due to braking of an aircraft flight by the cable brake device from the minimum level-flight velocity (or even cruising flight) of the aircraft up to its stop.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject of the invention is explained by drawings, wherein:

FIG. 1 is a side, perspective view of the aircraft in the preferred embodiment (different from the unmanned airplane “Pchela-1T” by the low wing) of the present invention with the pushing propeller in the tail and the arrested hook with the force element performed as a shank. The aircraft is shown going to cable landing in the level flight

FIG. 2 is side, perspective view of the least preferable aircraft (I1-103) with the pulling propeller in the front fuselage and a arresting hook with the force element performed as two bars. The aircraft is shown going to cable landing (landing angle 10°) in the level flight

FIG. 3 is two views: a top, perspective view of two-bar removed arresting hook is provided on a schematic background of the aircraft of FIG. 2 and a side, perspective view of that hook

FIG. 4 is the view I zoomed in five times being the part of FIG. 3 where the crosspiece connecting the arresting hook bars ends is shown.

FIG. 5 is the stages of cable landing of the unmanned airplane of FIG. 1 employing by the first analogue cable landing and braking device.

FIG. 6 is graphs of settlement parameters change of I1-103 airplane landing to a cable equipped with the arresting hook under the present invention (a) and under the—prior art—second analogue (b). The invention embodiments follow from the below descriptions of aircrafts.

THE BEST EMBODIMENT OF THE INVENTION

The aircraft (FIG. 1) realized under a normal design circuit has a fuselage 1 and a carrying wing 2 low located in the center fuselage. In the aft fuselage there is the pushing propeller 3 arranged in annular empennage 4. The brake device onboard part comprises a arresting hook 5 with grip 6, a shock-absorber 7 and a arresting hook drive for hook reduction from removed position (shown by dotted lines) into the deployed position (shown by continuous lines); the hook drive and the propeller engine are not shown to avoid shading of the aircraft essential elements).

The arresting hook 5 is provided with an opportunity of turn around the transversal axis 8 (shown by a circle with a point) located within the longitudinal interval of a mean aerodynamic chord, and also higher and behind the center of mass 9 (shown by a circle with shaded sectors). The stroke-dotted line passing through the aircraft center of mass and the crossing point of the axis 8 with the aircraft main plane refers to as the balance line 10. The longitudinal interval occupied by the mean aerodynamic chord is shown on the fuselage by two dotted lines, perpendicular to the center line 11.

In the deployed position the arresting hook is set in such a way that grip 6 appears above the aircraft leading for landing. Thus, the trajectory 12 of the grip 6 top pickup point of the aircraft on landing horizontally appears above the trajectory 13 of the aircraft top pickup point (in this case this is the top point of annular empennage 4), and higher than the cable 14. In turn, the trajectory 13′ of the highest point of the aircraft located ahead of the arresting hook passes below the cable.

The shock-absorber 7 is shown on the figure by dotted lines in the removed position.

Variants of the Embodiment

The aircraft (FIG. 2) is also realized under a normal design circuit. In the front fuselage 1 the pulling propeller 3 is installed, and in the alt fuselage—an elevator 15 and fin 16. Moreover, in the aft fuselage below the horizontal tail the deployed arresting hook 5 characterizing the—prior art—second analogue is conditionally shown by one dotted line. The hook drive and shock-absorber, and also the propeller 3 engine are not shown in this FIG.

This aircraft embodiment is the least preferable since the trajectory 14 of the aircraft top pickup point is the trajectory of the top point of the propeller rotation disk which passes below the cable 14 in a dangerous affinity thereto. For partial compensation of this disadvantage the aircraft arresting hook should be almost one third longer than the device of FIG. 1 at relatively comparable dimensions.

In the removed position the arrested hook 5 is shown by dotted lines.

Except for the above listed variants, the claimed aircraft is perfectly applicable to the gliders, and also for jets characterized by one fin and the engines located under the wing or in the aft fuselage. For airplanes with an out board fin the arresting hook lengthened almost twice is required (However, if a starting carriage constantly available at a landing place is applied instead of gear, such airplane will possess all advantages of the claimed aircraft).

The arresting hook (FIG. 3), for example, for passenger aircrafts (as in FIG. 2), is realized by a traverse comprising two bars, namely a hook 5 force element and a crosspiece-grip 6 between the put forward bar ends. Bars are located outside of fuselage and established with an opportunity of rotation around of the general axis 8. The hook is shown in the removed position, and the top view is given on the aircraft contour background.

In case of need the grip 6 has a lock executed as overhanging spring-stopper 17, attached to the hook bars by means of the crosspiece 18 keeping the stopper 17 locking (free) end in position of the grip 6 entrance overlapping in not less than half. Springing properties of the stopper 17 are demonstrated by that the cable passing into the grip 6 but cannot leave the grip.

The internal base grip surface 6 (FIG. 4) has a rounded form represented by dotted line with the radius R1 which should be not less than two cable diameters in order to increase the cable 14 durability.

The brake device stationary part (FIG. 5) is shown in the course of operation in four working positions (a, b, c, d), and is borrowed with some simplifications from the first analogue in which such stationary part is named as the moorage device.

This device (FIG. 5 a) comprises two identical jib load-lifting cranes located at the landing site at the distance excluding damage of the aircraft at landing and subsequent transportation to the parking area, and mutually connected by the strained cable 14. The positions b, c, d show the schematic image of the landing device depending on influence of the hooked aircraft.

Each load-lifting crane comprises sliding telescopic jib 19, established with the help of the hinge support 20. The telescopic jib 19 through the hinge is connected to the rod 21 of hydraulic cylinder 22.

On the end of the top section of each jib 19 in two-degree-off-reedom suspension 23 the oil-air shock-absorbers 24 with rods 25 are provided. The coming out rods 25 of the shock-absorbers 24 are directed towards each other by axis of the cable 14 fastened to the said rods.

On the landing place a catapult 26 with the carriage 27 can be provided for a particular type of the aircraft.

The aircraft landing is based on the direct braking effect of the aircraft leading for landing after the aircraft engaging by the catching cable of the brake device stationary part

If the air resistance is not taken into account, all aircraft movement changes after catching at the cable are reduced to the flight braking by the stationary brake device on the horizontal plane (the flight brake way), to lowering the aircraft on a vertical and to the aircraft turning around the transversal axis due to braking force from the brake device stationary (both horizontal and vertical) and to action of gravity. trasversal axis due to braking force from the brake device stationary (both horizontal and vertical) and to action of gravity.

The Table below results dependence of the flight brake way and the flight braking time of various types of airplanes depending on an overload arising at braking of the airplane flying with the minimal level velocity, from the moment of the airplane catching up to the stop of its horizontal movement

In this table the flight brake way and the flight braking time in horizontal movement are given by the following formulas: Flight brake way: S=V ² _(x)/2a Flight braking time: T=V _(x) /a where

-   V_(x)—landing speed (km/s); -   a—flight deceleration (m/s²)

(or, dividing by 9,8 miss one obtains the flight deceleration expressed in overload units) Deceleration Landing Aircraft Landing (overload speed V_(x) Brake way: S Braking time model (notes) weight (kg) units) (m/s) (m) T (s) 1. Pchela-1T 138 5 33 11.1 0.67 unmanned 138 10 33 5.6 0.34 2. IL-103 (3 1360 1 35 63.5 3.57 passengers) 1360 1.5 35 41.7 2.38 1360 2 35 31.25 1.79 3. Yak-40 (32 15500 1 56 160 5.72 passengers) 15500 1.5 56 106.7 3.81 15500 2 56 80 2.86 4. F/A-18 25400 3 69 81 2.35 Hornet (1 25400 4 69 60.7 1.76 pilot) 25400 5 69 48.6 1.4 5. Boeing 340000 1 66 222.3 6.72 747-200B 340000 1.5 66 148.2 4.49 (300 340000 2 66 111.15 3.37 passengers)

The overloads values from 1 up to 2 are not limiting. It is known, that airplane Concord had longitudinal overloads up to 2.5.

The aircraft landing to the cable begins with the aircraft approach the landing zone and the aircraft turning in the landing direction to the catching cable strained perpendicularly at the landing site (FIG. 5 a). Then the aircraft arresting hook 5 is put forward into “let out” position (if the later is not in constantly deployed position) and the aircraft is guided by the pre-set glide path, that in the most simple and most convenient variant means a level-flight minimum velocity in such a way that all aerodynamically significant elements pass below the cable, and the brake hook grip 6 is caught by cable 14 strained whenever possible in horizontal plane (small cable sag under action of the weight is inevitable).

Let us consider a particular case of the most preferable embodiment of the aircraft of FIG. 1.

FIG. 5 a shows a unmanned plane similar to “Pchela-1T” leading for landing with minimum level-flight velocity V_(x), which is in this case the airplane landing velocity for landing to the cable. This velocity in the FIG. 5 is directed from right to left. Thus on a side view the trajectory 12 of the grip 6 top point appears above the cable 14 (which is in the circular projection center of the shock-absorber 24 cylinder), and the trajectory 13 of the airplane top pickup point placed ahead the arresting hook appears below the cable 14. On the top view the airplane flight trajectory passes approximately in the middle of the cable 14 length and perpendicular to the said.

Under such airplane flight circumstances the arresting hook 5 meets the cable 14 and as a result of the cable and hook interaction, the latter deviates backwards, comes nearer to the balance line 10, and due to the airplane movement the hook slides along the cable, which plunges the spring stopper 17, slides near the said stopper and enters into grip 6. The spring stopper 17 returns into the initial position and prevents the cable 14 going out the grip 6. Fluctuations of the arresting hook 5 during the cable catching are damped by the shock-absorber 7.

After cable catching the airplane by inertia continues the flight corrected by the braking force from the cable 14 fixed on the air-hydraulic shock-absorbers 24 rods. By the airplane inertia force two-degree cardan suspensions 23 provide the shock-absorbers 24 cylinders turn both on horizontal and vertical planes. Thus the cable 14 sags down (FIG. 5 b) and extends the rods 25 from the swinging cylinders of the shock-absorbers 24. The resultant of extension forces of rods 25 of shock-absorbers 24 represents the braking force applied to the airplane through the arresting hook 5.

As a result of the braking force action the airplane flight velocity is slowed down, and, due to the braking force upward component, the airplane rises upwards at a fraction of a second. Thus the arresting hook 5 continues to deviate back in respect to the airplane and passes the balance line 10; then the airplane receives an increasing pitch-up moment M₂ from braking force causing the airplane turn (FIG. 5 a, FIG. 5 b). But at the airplane flight velocity reduction the lifting force is reduced, therefore the airplane gradually falls downwards with increasing vertical velocity, and because of the airplane rotation the arresting hook 5 turns forward, and back passes the balance line 10, then the airplane receives pitch-down moment from the braking force which aspires to return the aircraft into the level-flight position.

In case of the axis 8 arrangement in the center of mass 9 (achievable in the extremely rare cases), the airplane practically does not have the pitch moment and all deviations from level flight are due to change of the braking vertical force component.

At last the airplane level-flight velocity is slowed down to zero (FIG. 5 c), and sagging of the cable 14 reaches the maximum (the sag value projected on the horizontal plane is equaled to the airplane brake way), and since the airplane mass is not enough for holding the extended rods 25 in the former position so the shock-absorbers 24 involve the rods practically at half. In result the cable sag decreases. The airplane remains suspended on the cable by gravity and engine thrust and turns into a physical pendulum, which fluctuations are damped by the shock-absorbers 24, deviation of jibs 19 under action of hydraulic cylinders 22 and control of the engine thrust.

Then the airplane is lowered on the airfield or on the carriage 27 of catapult 26 (FIG. 5 d), synchronously turning the jibs 19 around the support 20, then the engine is cutoff. Other variant considers holding the airplane at some height due to an initial strain of the cable 14, by means of return of shock-absorbers 24 rods into the starting position, and then lowering the airplane by the first variant. Thus the cable hanging airplane inclination depends on the balance line 10 deviation from vertical and from the engine thrust compensating such deviation.

Thus, it is possible to perform the landing to the cable of the aircrafts similar to the unmanned airplane “Pchela-1T” or light models of planes and gliders with the landing speed of 15-35 m/s, for which the flight brake way (5.6 meters) is comparable with the stretched length of the rod 25 (1,5 meters) of the air-hydraulic shock-absorber 24. The similar landing brake device will be able used for the passenger airplanes with the flight brake way of 40-65 meters, but in this case the hydraulic pneumatic shock-absorber established instead of the hydraulic cylinder 22 must be the basic damper element. Then extension of the rod 21 of 2 meters at the cable rise height of 60 meters gives the flight brake way of up to 65 meters, due to the jib 19 turn.

For the airplanes with the flight brake way exceeding 70 meters, it is expedient to strain the catching cable 14 with the help of brake drums established on elevating cranes or other devices, providing the cable tension at the heights exceeding the aircraft flight brake way.

For the proof of advantages of the claimed aircraft in comparison with ((known)) the second analogue FIG. 6 shows separate calculated parameters of two embodiments of the aircraft similar to the airplane I1-103 (FIG. 2) and landing to the cable:

-   -   a—with the arresting hook 5 which turn axis is located according         to the claimed invention at 0.05 meters above and at 0.1 meters         behind the center of mass of the aircraft braked by the cable;     -   b—with the arresting hook 5′ located in accordance with         ((known)) the second analogue (shown by a dotted line in FIG. 2)         in the aircraft tail.

FIG. 6 shows above the following graphs: changes of the pitch moment (M_(z)), influencing the aircraft by the braking force; turn angle α from influence of M_(a); sinking velocity V_(y) and value of the aircraft descend h. (Continuous lines show the parameters according to the present invention, and dotted lines—in accordance with ((known)) the second analogue, while S=72.5 m and T=4s).

As seen from the mentioned graphs, by the end of braking (the fourth second) the aircraft equipped with the—prior art—second analogue arresting hook has fivefold change of direction of the pitch rotation moment M_(z) which amplitude accrues from 860 N·m up to 16230 N·m. According to the phase backlog the angular speed and angular acceleration change, as well as the aircraft turn angle α due to influence of M_(z)—from plus 0.3 degrees to minus of 43.5 degrees in the end

If to this aircraft break test (or to periodic “whip”) the aircraft hanging on the cable with the tail upwards after the stop is added, the unfitness of cable landing of such aircraft, especially with passengers, becomes obvious.

At the same time the claimed aircraft is characterized by an insignificant pitch moment Mz—from zero to plus 514 N m and then to minus 339 N m, due to which the aircraft smoothly takes the angle α from zero to plus 21.5 degrees. Besides, by the claimed invention at the end of braking the sinking velocity V_(y) is approximately at 11% less, and the descent h is at 20% less than that of the—prior art—second analogue device because the braking force vertical component of the claimed aircraft is constantly directed upwards, and in the—prior art—second analogue device the said component in first half of the braking cycle is directed downwards. Smaller sinking velocity and size of descent of the aircraft allow reduction of the catching cable 14 fastening height, i.e., the jib 19 height.

At preservation of the prototype advantages against the second analogue (technical characteristics: absence of “Whip” effect; reduction in requirements to the pilot qualification; reduction in requirements to the aircraft durability properties; reduction in cost of the aircraft, the ship accepting the aircraft and the pilot training), the claimed invention in comparison with the prototype has the following technical characteristics:

Increase of cawying capacity. (Unmanned virtual plane—“Pchela-1T” in mass of 138 kg is distinguished from the prototype by an uncontrolled parachute in mass of 4 kg and availability of four spring support in mass of 16 kg. Having removed the spring support and uncontrolled parachute, but having added a controlled parachute equipped with service systems of lump 8-12 kg, one obtains the unmanned prototype. If a controlled parachute is removed from such virtual prototype, but the arresting hook system is added (length of a hook 0.7 m) with the lump up to 4 kg, the weight of the claimed aircraft shall be at 4-8 kg smaller than that of the prototype. In result the aircraft useful loading in weight of 122 kg will increase from 25 kg to 16 kg-32% approximately—, for example agricultural aircraft having empty mass 50 kg and 8 overload units may have 2-3 kg smaller if the support device in mass 0.5 kg is removed from such virtual prototype. It is about 5-8% of carrying capacity.

Reduction of cost basically occurs due to reduction in—the aircraft labor input of the arresting hook service in comparison with labor input of the paraplane service (that is obvious) and in part by—the aircraft cost.

Increase of reliability of landing, firstly, due to the absence of—paraplane and abnormal situations connected thereto; second, due to more exact targeting of the brake hook on the gripping element, owing to smaller windage of the brake hook aircraft, than that of the paraplane aircraft; and thirdly, due to absence of centrifugal overloads after gearing (in the prototype the aircraft turns together with the jib)—the support device: secondly, due to absence of support moving and thirdly, due to absence of calculation of support moving quantity. i.e. there is no probability of aircraft crash because of incorrect putting of the support

The basic technical result—expansion of application field (arsenal) of the off-aerodrome landing aircrafts due to the absence of probability of aircraft crash because of incorrect putting of the support and due to known landing system (the first analog) and new use of the known landing system (the second analog).—option of landing to the cable of any aircraft with the aerodynamic significant elements which do not prevent the arresting hook deployed upwards functioning, known from the prior art. The majority of airplanes, gliders and model aircrafts are related to such aircrafts. Easy landing in comparison with the air field landing is explained by simplicity of the aircraft control (flight on horizontal or planning trajectory) and smaller wind shift on the height.—

In particular, the described landing to the cable of the unmanned airplane can be accomplished thousand and thousand times without crash of the aircraft while for unmanned plane “Pchela-1T” only five parachute landings are guaranteed.

That is, the unmanned airplanes for the first time can find commercial application in agricultural aviation and even can supersede therefrom all manned airplanes.

Also for the first time the off-aerodrome cable landing of passenger airplanes can be economically beneficial. Hence, light small-noise airplanes can be landed to the cable highly above the buildings even in the center of any city. Another application includes the cold climate areas where the cost of construction and operation of aerodromes is very high.

Off-aerodrome landing for regular operation of aircrafts demands off-aerodrome fly-off i.e., catapults are necessary for civil aviation. Having comprehensible at cost and operational parameters catapults with operation motion from 50 up to 150 meters, it is possible to transfer all civil aviation to off-aerodrome service. First of all this is applicable at the locations having insufficient space for full structure aerodromes. For example, the cost of the embanked sea airport of Hong Kong for reception of heavy passenger airplanes was 12 billion US dollars. It is obvious, that the airport including a catapult and cable landing device would cost in 3-5 times less.

It should be added that the expected technical result of the claimed aircraft includes the reduction of flight accidents connected to gear failure, since arresting hook reliability is much higher than reliability of the removed gear.

EXPLOITATION IN INDUSTRY

The claimed aircraft structurally differs from the known conventional aircraft with a deck arresting hook, for example, from the single fin airplane American A-6 “Intruder”:

-   -   1—by the hook fastening place (in the wing middle aerodynamic         chord longitudinal interval and in the fuselage tail part,         respectively),     -   2—by the deployed hook position (grip higher or lower the         aircrat, respectively), and     -   3—the declared device may have no traditional gear.

All above mentioned distinguishing features either improve the claimed aircraft (1 and 3), or are equivalent to each other (2).

Therefore, the production and application of the claimed aircraft is not more difficult, than that of a conventional one. 

1. An aircraft comprising a lifting wing and an arresting hook with a grip, which placed on the arresting hook with possibilities of letting out above the landing aircraft in order to be engaged with the catching cable of the landing and braking device situated at landing site, said arresting hook is mounted on the aircraft with possibility of turning around the transversal aircraft axis as result of engagement, said the transversal axis is located within the longitudinal interval of the mean aerodynamic chord of the wing, above and behind of the center of aircraft mass.
 2. An aircraft according to claim 1 is characterized by that the transversal axis of turning of the arresting hook is located immobile with respect to aircraft. 